Your first step is to uninstall all unnecessary programs installed on your computer (like third-party games, demos and other freebies, in the Add/Remove Programs control panel.
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Get, install, update and run free Ad-aware (and its HexDump plug-in) from
http://www.lavasoftusa.com/software/adaware/
First in the main window look in the bottom right corner and click on Check for updates now and download the latest referencefiles.
Make sure the following settings are made and on -------ON=GREEN
From main window :Click Start then Activate in-depth scan (recommended)
Click Use Custom Scanning Options' then click Customize' and have these options selected: Under Drives and Folders put a check by Scan Within Archives and below that under Memory and Registry put a check by all the options there.
Now click on the Tweak button in that same window. Under Scanning engine select: Unload recognized processes during scanning and under Cleaning Engine select: Let windows remove files in use at next reboot
Click proceed to save your settings.
Now to scan just click the Next button.
When the scan is finished mark everything for removal and get rid of it.(Right-click the window and choose select all from the drop down menu and click Next)
Restart your computer.
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You might post exactly what programs you have in the Add/Remove Programs Control Panel list box.
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Go to
http://housecall.trendmicro.com or
http://www.pandasoftware.com/activescan/com/activescan_principal.htm and click the Scan Now link to run a free on-line virus scan.
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What anti-virus are you using? If you're running Mcaffee or Norton anti-virus and have not recently paid for a one year subscription to download weekly new virus definitions, you might consider getting free AntiVir 6 (see berlow in my signature for the colored link) from
http://free-av.com - Uninstalling Mcaffee; Restarting your computer and installing free AntiVir Anti-virus 6.0.